Field of the Invention
The invention relates to an electronic compass having an electronic magnetic field sensor which is in a fixed position relative to a compass housing. The electronic compass also has a magnet mounted rotatably relative to the magnetic field sensor and is independently aligned with the terrestrial magnetic field. The electronic magnetic field sensor is located within the range of influence of a magnetic field generated by the magnet. The electronic magnetic field sensor has a first magnetoresistor with a fixed reference axis, whose electric resistance is a function of an angle of rotation between the fixed reference axis and the direction of the magnetic field. The magnetoresistor is arranged in a differential bridge circuit which supplies an output: voltage dependent on the angle of rotation.
A device for detecting an angular position of an object with respect to a prescribed zero position and having a magnetoresistor (MR) sensor which has a fixed reference axis and is arranged in a magnetic field is disclosed, for example, in published European Patent Application 680 614 B1.
U.S. Pat. No. 4,640,016 discloses a compass in which magnetoresistive sensors are arranged in the magnetic field of a magnetic compass. The sensitivity, that is to say the resolution with reference to the angle of rotation of the compass is, however, not satisfactory, because of the excessively low sensitivity of the magnetoresistive sensors.